Distributor unit

ABSTRACT

A distributor unit (D) includes a stepwise moving conveying line (L) for conveying containers (C) through one filling unit (G), where the containers (C) are filled with a predetermined filling liquid or powder substance. In a weighing station ( 15, 16 ), associated to the conveying line (L), two weighing groups ( 11, 12 ) are situated on opposite sides of the conveying line (L) and have one weighing area ( 14   a,    14   b ) for weighing a container (C). One transfer group ( 30 ) is associated to the weighing station ( 15, 16 ) and moves crosswise to the conveying line (L). The transfer group ( 30 ) transfers containers (C i ) to be weighed from the conveying line (L) to the weighing area ( 14   b ) of one of the weighing groups ( 12 ), and transfers at the same time an already weighed containers (C* i−1 ) from the area ( 14   a ) of the other weighing group ( 11 ) to the conveying line (L).

BACKGROUND OF THE INVENTION

[0001] The present invention relates to units for filling containers, inparticular bottles, with liquid or powder substances, in pharmaceuticalfield, e.g. medicines, or in cosmetics, e.g. perfumes.

[0002] More in particular, the present invention relates to adistributor for controlled filling of containers by checking the weightof the substance introduced therein.

DESCRIPTION OF THE PRIOR ART

[0003] It is known that it is necessary to respect strict weighingprinciples while filling bottles or containers with e.g. medicines,since the introduced substance must have a precise weight or volume.

[0004] Consequently, the tolerances admitted during containers fillingand batching steps are very restricted. It is therefore necessary toverify the weight of containers coming out from the filling station.

[0005] According to this procedure, sample containers are selected fromthe conveying line at selected time intervals and weighed.

[0006] If the container weight does not fall within the admittedtolerance, the product quantity delivered at the filling station isadjusted.

[0007] After having been removed from the conveying line and weighed,the sample container is rejected.

[0008] The sample containers must be rejected, because difficulties andconstructive problems of suitable operating means, which allow torecycle the rejected containers, have not been resolved yet.

[0009] The statistical weighing technique allows to weigh the containersvery precisely out of the conveying line, however, it does not allowtheir reintroduction in the productive cycle.

[0010] Moreover, since the check is performed on statistical basis, itis possible that, after being packaged and sealed, the weight of somecontainers does not fall within the admitted tolerances.

[0011] According to another method, used at present, the containers areweighed directly on the conveying line, at the outlet of the station forfilling the containers.

[0012] The conveying line features, arranged in predetermined positionsand at predetermined space intervals, suitable weighing stationspositioned in the regions of indentations or breaks of the conveyingline.

[0013] Although this weighing method allows to check the weight of allcontainers coming out of the filling station, on the conveying line, itpresents some operation problems with the detection of the containersactual weight.

[0014] The positioning of the weighing stations directly on theconveying line, which must move forward with a predetermined speed tomaintain best production rate, can cause some weighing problems due toinertia.

[0015] Actually, it is difficult for the containers to get settled andsteady in the weighing station within a time sufficient to acquire aprecise measure.

[0016] An operation unit for feeding containers which allows to feedcontainers along a conveying line and to transfer them from theconveying line to a weighing station, situated along the conveying line,is disclosed in the Italian Patent Application No. BO2000A 000147 of thesame Applicant.

SUMMARY OF THE INVENTION

[0017] The main object of the present invention is to propose adistributor unit, which allows to avoid the problems occurring in theprior art, and more precisely, a distributor unit, which allows to weighthe substance introduced into the containers in an extremely precise andeffective way.

[0018] Another important object of the present invention is to propose adistributor unit which enables to weighing all the containers,completely clear of the conveying line, and reintroducing the weighedcontainers thereto.

[0019] A further object of the present invention is to propose adistributor unit, which rejects containers, whose weight does not fallwithin the admitted tolerance.

[0020] The above mentioned objects are obtained, in accordance with thecontents of the claims, by a liquid substance distributor unitincluding:

[0021] a conveying line, which moves forward stepwise, so as to conveycontainers in a forward direction;

[0022] at least one filling unit, where said containers are filled witha

[0023] liquid substance;

[0024] at least one weighing station, associated to said conveying line;

[0025] said distributor unit (D) being characterized in that saidweighing station includes, in combination:

[0026] at least one first weighing station, situated upstream of saidfilling unit with respect to said forward direction (Z) of said line, soas to weigh the containers before filling;

[0027] at least one second weighing station, situated downstream of saidfilling unit, with respect to said forward direction of said line, so asto weigh containers after filling;

[0028] a control unit, interfaced with said first weighing station andwith said second weighing station, so as to acquire the weight of saidcontainers, respectively before and after filling, and determine the netweight of the substance introduced in each container;

[0029] with each one of the above mentioned first and second weighingstations including:

[0030] a first weighing group and a second weighing group situated onopposite sides of said conveying line;

[0031] at least one weighing area for each of said first weighing groupand second weighing group, for weighing a container conveyed by theconveying line;

[0032] at least one transfer group for transferring, during a conveyingline stop, containers to be weighed from said conveying line to theweighing area of said second weighing group, and for transferring, atthe same time, an already weighed containers from the first weighinggroup to said conveying line;

[0033] said transfer group transferring, during a next stop of saidconveying line, further containers to be weighed from said conveyingline to the weighing area of said first weighing group, and transferringat the same time, an already weighed containers from said weighing areaof said second weighing group to said conveying line.

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The characteristic features of the present invention will bepointed out in the following description of a preferred, but not onlyembodiment, with reference to the enclosed drawings, in which;

[0035]FIG. 1 is a schematic front view of the proposed distributor unitas a whole;

[0036]FIGS. 2a and 2 b are section views, taken along the II-II of FIG.1, of basic elements of the proposed distributor unit, in two differentoperation configurations;

[0037] Figures from 3 a to 3 d show working steps, according to afunctional scheme, of weighing the containers present on the conveyingline of the proposed distributor unit, while

[0038] Figures from 4 a to 4 d show working steps, according to afunctional scheme, of weighing when the distributor unit is operated.

BEST MODES OF CARRYING OUT THE INVENTION

[0039] With reference to the enclosed drawings, in particular FIG. 1.the distributor unit, proposed by the present invention, is indicatedwith reference numeral D.

[0040] The distributor unit D includes a conveying line L, which movescontainers C stepwise in a horizontal direction Z, so as to move thecontainers to a filling unit G, which fills the containers C with apredetermined liquid substance.

[0041] The distributor unit D includes also, upstream of the fillingunit G, a first weighing station 15, and downstream of the filling unitG, a second weighing station 16.

[0042] The containers C_(IN), which enter the filling unit G, areweighed in the first weighing station 15, before being filled, so as todetermine the weight of the empty containers, or tare weight.

[0043] The containers C_(OUT), which leave the filling unit G, areweighed in the second weighing station 16, after filling, so as todetermine the containers gross weight.

[0044] Each of the weighing stations, first weighing station 15 andsecond weighing station 16, is equipped with e.g. a pair of weighinggroups, namely a first weighing group 11 and a second weighing group 12.

[0045] The first weighing group 11 and second weighing group 12, asshown in detail in FIGS. 2a and 2 b, are situated external to theconveying line L, facing and parallel to each other.

[0046] Each of the first and second weighing groups 11 and 12, isequipped with at least one weighing area, a weighing area 14 a and aweighing area 14 b, respectively, which receives a correspondingcontainer C and weighs it.

[0047] In particular, for sake of clarity, FIGS. 2a and 2 b show onlyone of the weighing areas 14 a and 14 b for each weighing group, first11 and second 12, and consequently, for each weighing station, first 15and second 16. However, according to other, not shown embodiments of thedistributor unit D, each weighing group can be equipped with a pluralityof weighing areas 14 a, 14 b for weighing more containers C at a time.

[0048] According to FIG. 2b, each weighing area 14 a, 14 b includes oneseat, 140 a and 140 b, respectively, which houses a correspondingcontainer C being weighed.

[0049] A unit 141 a and 141 b is associated to the seat 140 a, 140 b,respectively, for acquiring the weight of the container C.

[0050] Each of the above weighing stations, first 15 and second 16,features a transfer group 30, which is situated over and crosswise, asshown in FIGS. 2a and 2 b, with respect to the direction Z, indicated inFIG. 1, along which the containers C move forward on the conveying lineL.

[0051] The transfer group 30 extends from the first weighing group 11 tothe second weighing group 12 of the relative weighing station 15 or 16.

[0052]FIGS. 3a and 3 b show a typical step of the conveying line Lforward movement and a weighing station 15, 16, associated thereto.

[0053] As shown in the above Figures, the transfer group 30 transferscontemporarily containers C_(i) to be weighed, moved by the conveyingline L in the region of the weighing station 15 or 16 toward the secondweighing group 12 of the same weighing station 15 or 16, and the weighedcontainers C*_(i−1), situated on the first weighing group 11 of theweighing station 15 or 16 toward the conveying line L (arrow T1)crosswise to the direction Z.

[0054] As it appears in FIGS. 3c and 3 d, which show a further typicalstep of the conveying line L forward movement and the weighing station15, 16, associated thereto, the same transfer group 30 transferssimultaneously further containers C_(i+1) to be weighed, moved by theconveying line L in the region of the weighing station 15, 16 toward thefirst weighing group 11 of the same weighing station 15, 16, and theweighed containers C*_(i), from the second weighing group 12 toward theconveying line L (arrow T2) crosswise to the direction Z.

[0055] For sake of clarity, in the above description and the enclosedfigures, C_(i) indicates containers to be weighed, and i=1, . . . , Nindicate containers fed by the conveying line L toward the weighingstation 15, 16, where N indicates the progressive number of thecontainers conveyed by the conveying line L, and C*_(i) indicates theweighed containers leaving the weighing station 15, 16 toward theconveying line L.

[0056] As seen for example in FIGS. 2a, 2 b, each transfer group 30 isequipped with a relative pair 32 of clamping grippers 31 carried bydriving means 33.

[0057] The driving means 33 are slidably coupled with guiding means 34to drive the pair 32 of clamping grippers 31 to reciprocate crosswise tothe direction Z (arrow F in FIG. 2a).

[0058] In particular, the distance between the above mentioned clampinggrippers 31 of each pair 32 corresponds to the distance between theweighing area 14, respectively 14 a and 14 b of each weighing group,first 11 and second 12, respectively, and the conveying line L.

[0059] According to the non limitative example shown in the abovementioned Figures, the transfer group 30 associated to the weighingstations, first 15 and second 16, is equipped with only one weighingarea, respectively 14 a and 14 b, for each weighing group, first 11 andsecond 12, respectively, and includes only one pair 32 of clampinggrippers 31.

[0060] If the weighing groups 11, 12 are equipped with a plurality ofweighing areas, the transfer group 30 associated thereto will include anumber of pairs 32 of clamping grippers 31, which will correspond to thenumber of the weighing areas.

[0061] The proposed distributor unit D includes also a control unit U(FIG. 1), which is interfaced with the first weighing station 15 foracquisition of the empty containers C weight, as well as with the secondweighing station 16 for acquisition of the corresponding filledcontainers C weight.

[0062] The control unit U operates the conveying line L controlling thestepwise forward motion. The step of the conveying line movement isdetermined by the number of the weighing areas of each weighing group11, 12 of the weighing stations 15, 16.

[0063] Thus, each empty container C leaving the first weighing station15 is weighed and two values related thereto are stored in the controlunit U: the first value is the i^(th) position coordinate of the emptycontainer C along the line L and the second is the container weight.

[0064] In this way, on the basis of the i^(th) position coordinate, thecontrol unit U can recognize different containers C leaving the fillingunit G, while they are passing through the second weighing station 16and can associate the corresponding weight values to the containersfilled with the selected substance.

[0065] Therefore, the control unit U stores two different weight valuesfor each filled container C leaving the second weighing station 16, onecorresponding to the weight of the empty container C and the othercorresponding to the filled container C.

[0066] Thus, the control unit U can calculate the net weight of thesubstance, with which the containers C have been filled by the fillingunit G.

[0067] The control unit U is interfaced also with a rejection unit S,which is situated along the conveying line L, downstream of the secondweighing station 16, and removes from the conveying line L containers C,which have been filled with a quantity of substance, whose net weightdoes not fall within the admitted or desired tolerance.

[0068] A position sensor 4, also connected with the control unit U, issituated over the conveying line L, near the outlet of the firstweighing station 15.

[0069] The position sensor 4 counts the forward steps and verifies thecorrect stepwise forward movement of the conveying line L.

[0070] The position sensor 4 monitors also the correct positioning ofthe empty containers C, fed to the filling unit G by the conveying lineL, after they have been weighed.

[0071] Now, the operation of the proposed distributor unit D isdescribed, with particular reference to the Figures from 4 a to 4 d.

[0072] Figures from 4 a to 4 d show in an extremely schematic way, anexample of a weighing station 15, 16 associated to the conveying line L.

[0073] In the following description of the distributor unit D operation,the weighing illustrated station will be e.g. the first weighing station15.

[0074] Before operating the conveying line L, the operator place anempty container C*₀ in the area 14 a of the first weighing group 11 ofthe first weighing station 15.

[0075] Likewise, a filled container C (not shown) is placed in the area14 b of the first weighing group 11 of the second weighing station 16.

[0076] Then, the conveying line L is operated and moves stepwise in theforward direction Z.

[0077] In the shown example case, each weighing group 11, 12 is equippedwith only one weighing area and each forward step of the conveying lineL corresponds to the distance between the middle axes of two subsequentcontainers.

[0078] When the empty container C1 to be weighed reaches the firstweighing station 15 (FIG. 4a), brought thereto by the stepwise movementof the conveying line L, the transfer group 30 is operated.

[0079] The container C1 to be weighed, situated on the conveying line Lin correspondence to the first weighing station 15, is transferred, bythe relative pair 32 of clamping grippers 31 of the transfer group 30,to the seat 14 b of the second weighing group 12, and at the same time,the weighed container C*₀, situated on the area 14 a of the firstweighing group 11 is transferred, by the transfer group 30 to theconveying line L (FIG. 2b, FIG. 4b arrow T1).

[0080] In step relation with the end of the transfer operation, thecontrol unit U operates the line L to move one step forward (FIG. 4c,arrow Z), so as to bring the next empty container C₂ to be weighed tothe first weighing station 15.

[0081] During the forward movement of the line L, the weighing seat 14 bof the second weighing group 12 acquires the weight of the containerC*₁, situated thereon.

[0082] Then, the acquired weight value is stored in the control unit Uin combination with a position coordinate, which individuates theposition of the just weighed container on the conveying line L.

[0083] The transfer group 30 is operated at the subsequent stop of theconveying line L, so that the container C₂ to be weighed, situated onthe conveying line L in the region of the first weighing station 15, istransferred, by the relative pair 32 of clamping grippers 31 of thetransfer group 30, to the seat 14 a of the first weighing group 11,previously emptied.

[0084] At the same time, the weighed container C*₁, situated on the area14 b of the second weighing group 12 is transferred, by the transfergroup 30 to the conveying line L (FIG. 4d arrow T2).

[0085] In step relation with the completion of the transfer, the controlunit U operates the line L to move one step forward (FIG. 4c, arrow Z),so as to bring next empty container C₂ to be weighed to the firstweighing station 15.

[0086] The above operations are repeated sequentially and the controlunit U stores the weight values of the subsequent containers C fed toand passing through the filling unit G.

[0087] Moreover, each weighed empty container is given a correspondingposition identifying coordinate.

[0088] The position sensor 4 checks the correct position of the weighedempty containers C* on the conveying line L leaving the first weighingstation 15.

[0089] The sequence of the above described operation steps is repeated,in the same way, in the second weighing station 16 situated downstreamof the filling unit G.

[0090] Thus, the control unit U stores the weight values of the filledcontainers C leaving the second weighing station 16.

[0091] The control unit U can calculate the net weight of the substanceintroduced into the containers and verify if it falls within theadmitted tolerance by recognizing different containers on the ground oftheir position identifying coordinate.

[0092] If there is a container filled with the substance, whose netweight does not fall into the allowed tolerance, the rejection unit S isoperated by the control unit U and the container is removed andrejected.

[0093] Therefore, the proposed distributor unit D enables acquisitionand determination, with absolute precision, of the net weight of thesubstance introduced into the containers C fed by the conveying line L.

[0094] It is to be pointed out that the acquisition and determination ofthe net weight of the substance introduced into the containers C takesplace completely out of the conveying line, which advantageously avoidsweighing inertia problem.

[0095] Another advantage of the proposed distributor unit D derives fromthe fact that the weighing stations include extremely functional, andsimple elements, whose number is limited, thus reducing the productioncosts.

[0096] The weighing stations allow to remove the containers to beweighed from the conveying line, to weigh the removed containers and toreintroduce the weighed containers to the conveying line, withoutslowing down the conveying line forward movement, which permits tomaintain best production rate.

[0097] Moreover, the proposed distributor unit D enables removal andrejection of containers filled with a quantity of substance having a netweight which does not fall within the admitted tolerance.

[0098] Therefore, it is obvious that the proposed distributor unitallows to acquire the net weight of the substance introduced into thecontainers completely out of the conveying line by a sequence ofextremely efficient and easy operations.

1. A liquid substance distributor unit (D) including: a conveying line(L), which moves forward stepwise, so as to convey containers (C) in aforward direction (Z); at least one filling unit (G), where saidcontainers (c) are filled with a liquid substance; at least one weighingstation (15, 16), associated to said conveying line (L); saiddistributor unit (D) being characterized in that said weighing stationincludes, in combination: at least one first weighing station (15),situated upstream of said filling unit (G) with respect to said forwarddirection (Z) of said line (L), so as to weigh the containers (C_(IN))before filling; at least one second weighing station (16), situateddownstream of said filling unit (G), with respect to said forwarddirection (Z) of said line (L), so as to weigh containers (C_(OUT))after filling; a control unit (U), interfaced with said first weighingstation (15) and with said second weighing station (16), so as toacquire the weight of said containers (C), respectively before and afterfilling, and determine the net weight of the substance introduced ineach container; with each one of the above mentioned first and secondweighing stations (15, 16) including: a first weighing group (11) and asecond weighing group (12) situated on opposite sides of said conveyingline (L); at least one weighing area (14 a, 14 b) for each of said firstweighing group (11) and second weighing group (12), for weighing acontainer (C) conveyed by the conveying line (L); at least one transfergroup (30) for transferring, during a conveying line (L) stop,containers (C_(i)) to be weighed from said conveying line (L) to theweighing area (14 b) of said second weighing group (12), and fortransferring, at the same time, an already weighed containers (C*_(i−1))from the first weighing group (11) to said conveying line (L); saidtransfer group (30) transferring, during a next stop of said conveyingline (L), further containers (C_(i+1)) to be weighed from said conveyingline (L) to the weighing area (14 a) of said first weighing group (11),and transferring at the same time, an already weighed containers(C*_(i)) from said weighing area (14 b) of said second weighing group(12) to said conveying line (L).
 2. A distributor unit, as claimed inclaim 1, wherein each of said first weighing group (11) and secondweighing group (12) of said weighing stations (15, 16) includes aselected number of weighing areas (14 a, 14 b) and said conveying line(L) is controlled by said control unit (U) so as to move stepwise inrelation to said selected number of weighing areas (14 a, 14 b).
 3. Adistributor unit, as claimed in claim 1, further including a rejectionunit (S), situated downstream of said second weighing station (16) withrespect to said forward direction (Z) of said line (L) and interfacedwith said control unit (U), so as to remove and reject from theconveying line (L) containers (C) filled with substance and having saidnet weight out of an admitted tolerance stored in said control unit (U).4. A distributor unit, as claimed in claim 1, further including sensormeans (4) for detecting the position of said containers (C) on saidconveying line (L) and for counting forward movement steps of said line;said sensor means (4) being connected to said control unit (U).
 5. Adistributor unit, as claimed in claim 1, wherein said transfer group(30) includes: at least one pair (32) of clamping grippers (31) forgripping containers (C), said pair (32) being associated with a relativeweighing area (14 a, 14 b); driving means (33) slidably coupled withguiding means (34) for driving said pair (32) of clamping grippers (31)with a reciprocatory movement in a direction (F) crosswise to theforward direction (Z) of said conveying line (L).
 6. A distributor unit,as claimed in claim from 1, wherein each weighing area (14 a, 14 b)includes a relative seat (140 a, 140 b) for housing one container (C) tobe weighed, each of said seats (140 a, 140 b) being equipped with arelative acquiring unit (141 a, 141 b) for acquiring the weight of saidcontainer (C).